Differential Sounds Like A Jet Turbine

[hach1r0k1d03]

Long story short, I drove my car to break in a new weir performance ring & pinion plus all new rear end rebuild parts(pinion nut, seal, crush sleeve, pinion bearings, carrier bearings and pumpkin gasket) and my differential whines like a jet turbine. The sound disappears when I let off the gas but immediately returns on the slightest press. The sound is also gets way more intense approaching 70mph.

It sounds just like this youtube video of a jet turbine sound: (was safe to play for me but adjust your sound just in case)
https://www.youtube.com/watch?v=cvCZ1D9azm4

Anybody experience this or know what the issue could be? I was thinking maybe I adding some friction modifier might help? Gonna talk to the shop that did the work when they open but still want to see what anyone familiar corollas might know.

[allencr]

I was thinking maybe I adding some friction modifier might help? Gonna talk to the shop that did the work when they open but still want to see what anyone familiar corollas might know.

NO! There's no magic lubeor additive that can cure or even change any noise except something like going from H2O/urine to oil.
YES, definitely!
Does it also sound the same when letting off the throttle, when engine braking?

[hach1r0k1d03]

The sound seems to go away when letting off the throttle.

Had a worker from the shop that did the work drive it. They said the sound is typical for weir performance ring & pinions and that mine was not as bad as they've experienced with other corolla weir installs. Sounds iffy but they said to drive it for the rest of the break in procedure (300 miles) and if it sounds worse they would be willing to look at it again.

[tchybrid]

i would drive it a bit longer, as the new ring and pinions, the faces have not completely broken into each other yet.

[hach1r0k1d03]

Just drove home. Sound seems to occur even when not accelerating. It is quite loud and a bit unbearable. Even if this was a track car only hearing that noise would really suck. Hopefully it gets better.

[Resurrected]

In my experience a whining noise when throttle is applied (even lightly applied) is the pinion bearing. As I recall this problem usually occurs when the crush sleeve is crushed too much. Maybe someone with more experience setting up diffs can chime in and correct me if I'm wrong. I would not continue driving it until the problem is corrected, as you may risk damaging your new gear set. It is NOT normal for a ring and pinion to make a whining noise just because it's new. Good luck.

[allencr]

Whine during a so called break-in is 100% BS, there is almost ZERO breaking time with new gears & bearings, they just run a little bit hotter then usual for an hour or 2 at most- they're just hoping you'll go away and/or die.

DOES the whine disappear completely when off the throttle - zero load on the engine, the come back when engine braking/downshifting/putting the R&P load on the driven side rather then their drive side?
Bad setup will whine more under a light load/partial throttle and will usually disappear when putting more load on it, while bad/worn gears will whine/howl more the more load that they get.

[hach1r0k1d03]

DOES the whine disappear completely when off the throttle - zero load on the engine, the come back when engine braking/downshifting/putting the R&P load on the driven side rather then their drive side?

The whine doesn't seem to disappear when completely off the throttle.

I called up Weir Performance and they said it should be as quiet as OEM so I'm definitely going to have the shop look at the diff again taken out.

[InitialB]

Its unfortunate, but this is a common problem with Weir stuff. Their manufacturing is unreliable, so in most cases their gears won't be completely true. I'd say get that checked out ASAP.

[hach1r0k1d03]

Its unfortunate, but this is a common problem with Weir stuff. Their manufacturing is unreliable, so in most cases their gears won't be completely true. I'd say get that checked out ASAP.

Ah so this is common with Weir? I think that's what I was trying to confirm but can't seem to find anyone who could chime in with their parts. Sucks cus on one end I have the the shop that did the work saying "yeah this is common with Weir but your car is the quietest I've experienced" then on Spence from Weir's end I hear "yeah it has to be something wrong with the setup. I've never heard that issue on our parts but have heard it on OEM parts."

[totta crolla]

My Weir 4.778 sounds similar to yours and it had new bearings throughout.....

[BrianZ]

Its unfortunate, but this is a common problem with Weir stuff. Their manufacturing is unreliable, so in most cases their gears won't be completely true. I'd say get that checked out ASAP.

is there anyone beside weir is offering new r&p now?

[hach1r0k1d03]

My Weir 4.778 sounds similar to yours and it had new bearings throughout.....

Ah I see. Yeah I guess this means that taking the diff out and having the shop look at it would be pointless.

How long have you had your Weir? Just wondering if it's at least lasting pretty long.

[totta crolla]

Mine has been in for about 2 years and just whines, seems strong enough and to be fair it puts up with the abuse that rallying offers.
It made the noise from first fitment.
These guys do a 4.9 and a 5.4 (5.375) http://www.motorsport-tools.com/catalog ... lt/?q=ae86
I think Toyota also sold the 4.778

[InitialB]

Its unfortunate, but this is a common problem with Weir stuff. Their manufacturing is unreliable, so in most cases their gears won't be completely true. I'd say get that checked out ASAP.

is there anyone beside weir is offering new r&p now?

Basically just TRD. Maybe some specialty japanese shops too.

[Deuce Cam]

OEM Toyota (some may be discontinued): http://club4ag.com/faq_and_tech_pages/D ... inions.htm.

I've got the Toyo 4.778. Spence at Weir installed it with new oem bearings/hardware (and his solid pinion spacer) 3 years ago and it doesn't wine.

[allencr]

DOES the whine disappear completely when off the throttle - zero load on the engine, then come back when engine braking/downshifting/putting the R&P load on the driven side rather then their drive side?

The whine doesn't seem to disappear when completely off the throttle.

NOT completely off of the throttle, when easing off the throttle - it's the interval inbetween the engine putting power to the wheels and when the momentum/speed/inertia of the car is putting rpms into the engine, neither engine braking nor accelerating or even light throttle cruising to maintain speed.
Its bearings will Never whine when good or bad but maybe when setup super too tight, its R&P will almost always whine when making bad contact from being setup/positioned wrong.
Sure, the gears could be machined wrong, but unless they are which is almost never, a proper setup will never whine or hum or make any sound under load & deceleration.

[LongGrain]

it is typical to sometimes get a little bit of noise from a 4.77 final. If the noise is really that loud, it would be an indicator of an improper setup.

[b-rock]

It sounds like an improper setup to me too. It's a very, very fussy thing to set up a diff properly. Ask the shop if they use an impact gun to do ANY of the assembly and setup. If they do, go somewhere that does it right -- by hand. I've heard things about slightly noisy 4.77s from Weir -- but I bet they just have less margin for error for some reason and are therefore even more difficult to set up. The only way to know for sure is to take it out and run a contact pattern check (and check the preload to see how good the shop is).

[LongGrain]

^^^ Weir says right in his solid pinion spacer to reef the pinion nut down with an impact...

[b-rock]

^^^ Weir says right in his solid pinion spacer to reef the pinion nut down with an impact...

Impacting tapered roller bearings is just bad advice. With a solid spacer, it is a bit different, but with a crush sleeve it's a total no no because that torque is what gives the pinion bearing its preload -- and it's a touchy job. With a solid spacer, the shims set the preload and the pinion depth, so impacting just beats the bearings.